1. Field of Invention
The invention relates to an improved apparatus and process for repairing a damaged area to a planar surface. It is particularly useful in situations where the back side of the surface is inaccessible and the cosmetic appearance of the front surface is of importance such as in the repair of plasterboard walls.
2. Description of Prior Art
Heretofore, repairing a hole in a planar surface, such as a plasterboard wall involved several difficult steps and resulted in a cosmetically undesirable finish. The difficulties arise in trying to contain a fluent patching compound until it sets. Additionally, manually creating a finish that blends in with the existing texture and shape is difficult and often results in an "obvious repair". In trying to overcome these difficulties some methods for patching holes have been developed, however, none solve the need for a structurally sound repair as well as a cosmetically acceptable finish.
Several inventors have attempted to solve the problems inherent in this type of repair. U.S. Pat. No. 4,354,332 to Lentz (1982) describes an apparatus for repairing holes in drywall. Although it attempts to solve the problems of containment of a fluent patching compound, it requires a substantial size slot or hole in its front containment dam, which when in use, will allow said compound to extrude, leaving a bump on the surface of the repair. Additionally, the front dam and backing means being substantially rigid does not allow for pushing of said compound forward for a cosmetically unblemished surface. U.S. Pat. No. 4,100,712 to Hyman (1978) uses a non-slotted front dam and a metal "basket" shaped backing means for containment of a patching compound. Although front containment is smooth and uninterrupted, it provides no means for pushing said compound forward to eliminate gaps or bubbles. U.S. Pat. Nos. 4,193,243, 3,999,347, 3,874,505, 3,690,084, 3,373,467 present methods for holding a backing means in place with no mention of containment with a front dam.
These inventors have attempted to solve part of the problem. None, however, create a method that contains a patching compound, pushes said compound forward against a front dam to eliminate gaps or bubbles, and provides a means to copy the shape and texture of the existing surface.